Endoscopic surgery has been gaining wide acceptance as an improved and cost effective technique for conducting certain surgical procedures. In endoscopic surgery, a trocar, which is a pointed piercing device, is inserted in the body with a cannula placed around the trocar. After the trocar accomplishes piercing of the abdominal walls, it is removed and the cannula remains in the body. Often multiple openings are produced in the body with a trocar. Through these cannula, endoscopic procedures are possible. An endoscopic instrument may be placed in one cannula, an appropriate viewing mechanism placed in another cannula and the fiber optics for illuminating the surgical field in yet another cannula. Generally, these endoscopic procedures take place under insufflation. As more is learned about endoscopic procedures and more instruments developed, the type of procedures that may be performed endoscopically will increase. Presently, typical procedures are gall bladder removal, tissue repair, and various sterilization procedures.
Many of the instruments used in endoscopic procedures are used to join tissue, grasp tissue, or otherwise manipulate tissue. Such instruments usually have a pair of jaws which are placed about the tissue to be manipulated, then the instrument is activated to manipulate the tissue. As can be appreciated, it is often quite difficult to be certain you have the jaws positioned correctly to manipulate the tissue and/or you have the right amount of tissue between the jaws in an appropriate position to manipulate the tissue.
It is an object of the present invention to provide an instrument that will allow the user to know when he has the jaws of an instrument appropriately placed about tissue. In certain embodiments, it is an object of the present invention to control an instrument so that it cannot be activated until the jaws are in an appropriate position about the tissue to be manipulated. In other embodiments, it is an object of the present invention to provide a feedback device for tissue fastening parameters.